Fishy Wager

Science
Science brain teasers require understanding of the physical or biological world and the laws that govern it.

One day, John and Sue were out fishing in the Atlantic Ocean. When a shark swam by, Sue said, "I'll bet you ten dollars that the shark over there doesn't have a bone in its skeletal structure." John thought he would win this one, but he didn't.

How can this be?

Answer

With sharks being in class Chondrichthyes, the group of fish containing skeletons of cartilage, sharks do not have a skeletal structure of bones.